Hello, Jay and Goran
Thanks to Jay for describing his vision in detail, I find it useful. In audio, what makes it different from instruments design, not only textbooks and formulas lead to perfection.
Goran, in the modified PF99, as we both agreed, only one expensive HF transistor could be used per channel, the current source will be OK with 2SK1530. In the No NFB preamp, the K2199 has the same price range as K1530.
At the moment, I am building the cluster cap from 24 x 1000uFx63V SamWha WL series (arrenged in two 12pcs rings for providing equal signal path to each cap), plus 100uFx400V Solen polypropylene, shall report the impedance measurements.
Thanks to Jay for describing his vision in detail, I find it useful. In audio, what makes it different from instruments design, not only textbooks and formulas lead to perfection.
Goran, in the modified PF99, as we both agreed, only one expensive HF transistor could be used per channel, the current source will be OK with 2SK1530. In the No NFB preamp, the K2199 has the same price range as K1530.
At the moment, I am building the cluster cap from 24 x 1000uFx63V SamWha WL series (arrenged in two 12pcs rings for providing equal signal path to each cap), plus 100uFx400V Solen polypropylene, shall report the impedance measurements.
Thanks Vladimir,
For sure i will build your designs both of them follower and the preamp. Just i like to do it right, so i will need some time to collect all parts.
Vladimir, i would like to ask you, in my PF99, im loosing the current as fet's get heatted. The bigger heatsinks could solve the problem, but i would be glad to hear your opinion about.
Best regards
Goran
For sure i will build your designs both of them follower and the preamp. Just i like to do it right, so i will need some time to collect all parts.
Vladimir, i would like to ask you, in my PF99, im loosing the current as fet's get heatted. The bigger heatsinks could solve the problem, but i would be glad to hear your opinion about.
Best regards
Goran
Of course the new follower will be better. I'm also cutting price here with my IRF331. But I don't need to purchase anything to build my amps. I have more than enough components to try many designs.
Of course I'm building something
Problem is, I'm building too many things at once. Now I'm also preparing for Pinkmouse's BAKSA 200W (in Greg's Baby AKSA thread). The AKSA clone, has the strength to recreate good soundstage, especially the vocalist. Notice that this is still in line with my concept of the "holy grail".I had been prepared to build Vladimir's integrated amp. Now I decide to abort it and build the new preamp plus the amp instead. I haven't been prepared with the input P-channel FET. Will study my FET inventory soon (I think I only have J109). But I'm ready with the enclosure and heatsinks. And point-to-point drawing for the amp.
I think this happens because of the current sensing resistors have not enough dissipation ability (better to oversize them), and BD139 transistor is located near the hot parts. You should pay attention to this.
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That could be the reason, i have 2x0.47Ohm's / 10W per chanell, and yes BD139 is pretty close. The current goes down from 3A to 2.5A per chanell after 10 min. Maybe its not a big problem, cos i cant notice any differents in the sound.
I would like to make another PF99 but this time point to point wirring, so i could mount the ressistors on the separated heatsinks.
I still didnt try cap-cluster you suggested, cos i dont have enough space inside. I need bigger case to implement it.
I asked you once before about discrete active crossover, maybe you find some circuit meanwhile?
Best regards
Goran
I still didnt try cap-cluster you suggested, cos i dont have enough space inside. I need bigger case to implement it.
I asked you once before about discrete active crossover, maybe you find some circuit meanwhile?
Best regards
Goran
Hi, Goran
I would be glad to give you some useful info concerning active crossovers, but unfortunately I can not. Was not interested in this approach.
I am experimenting now with the cluster cap solution, trying to arrange something like a passive crossover (100uF polypropylene, then small L-big C, C is a cluster of electrolytes).
Hello, Miklos
I ask to excuse me, but I do not play with spectrum measurements. I consider a high quality system as the main instrument relevant to estimating audio quality. IMHO.
Hi Vladimir,
I understand, but you make all kind of other measurements.
Besides may be some other members think differently about evaluation of audio equipment. You presented your creation. Thank you. Now if I want to make up my mind about it, I would have to build one and measure it, while you already have it. It would be is easier if you would make the measurement.
Regards, Miklos
I understand, but you make all kind of other measurements.
Besides may be some other members think differently about evaluation of audio equipment. You presented your creation. Thank you. Now if I want to make up my mind about it, I would have to build one and measure it, while you already have it. It would be is easier if you would make the measurement.
Regards, Miklos
Hello, Miklos
I am grateful to you for the PCB efforts, this could make assembling a bit easier.
Now I have inserted the No NFB Preamp board into the integrated Son of Follower. At the same time, the preamp itself, with the few Ohms output impedance and excellent sound, worth wide use, and I understand that PCB is needed for this. Thanks for your support.
I am grateful to you for the PCB efforts, this could make assembling a bit easier.
Now I have inserted the No NFB Preamp board into the integrated Son of Follower. At the same time, the preamp itself, with the few Ohms output impedance and excellent sound, worth wide use, and I understand that PCB is needed for this. Thanks for your support.
Hello Vladimir
I thought you favorised a different aproach the PCB before
What abt point to point soldering?
Hello Vladimir
I thought you favorised a different aproach the PCB before
What abt point to point soldering?
Point to point is better, but possibly acceptable to only a few semi-normal guys, maybe I belong to them also.
So, I completely understand and support all those who will not go without PCB.
Hello Miklos,
Very nice board.
Im interested how your board looks from the side of components, what technique do u use to sign the placements of parts?
Best regards
Goran
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